Method and apparatus for pressure treatment



Aug. 31; 1937. LAUSSU'CQ 2,991,641

v METHOD AND APPARATUS FOR PRESSURE TREATMENT Filed Oct. 12, 1951 4 Sh'eets Sheet 1 Au 31, 1937 H. P. L. LAU-SSUCQ METHOD AND APPARATUS FOR PRESSURE TREATMENT Filed Oct.' 12, 1951 '4 sneets-snee 2' a 62 i rzgxaoz slauzz W Z) 1 1 6 u I 64 63 r 1937. 'I'QL'P. L. LAUSSUCQ I 2,091,341

METHOD AND APPARATUS FOR PRESSURE TREATMENT Filed Oct. 12, 1931 [Sheds-Sheet a i amwuun Patented Aug. 31, .1937

UNITED STATES METHOlj AND APPARATUS FOR PRESSURE TREATMENT Henri P. L. Laussucq, Reading, Pa assignor to Birdsboro Steel Foundry & Machine Company, Birdsboro, Pa... a corporation of Pennsylvania Application October 12, 1931, Serial No. 568,486

16 Claims.

My invention relates-to pressing operations. Most of my disclosure refers to impregnation by pressure against'sheet stock which is porous or fibrous, and is to be impregnated, or which is compressible and which is to be resiliently compressed. Where' impregnation is intended, a draining background'is contemplated, but this is not required where the operation is one of compacting instead. The portion of the invention applied to the sealing under pressure which is greater than the fluid pressure, is independent of the draining background or of the special material operated upon. Where the invention relates to scaling for other purposes, such as hereinafter described, for the purposes of sealing against pipe flanges or surfaces in liquid application to pipe for testing its resistance to pressure, the material of the work will ordinarily not be sheet stock .and need have no relation to the fibrous or porous or compactible character of the stock or of any part of it.

In order that the description may be clear and more easily understood, I have applied the in-- vention particularly to operation upon leather, either for filtering purposes through the leather to impregnate the leather or for pressing purposes upon the leather to compact it. Where reference is made to leather, it is the intention to have the term refer to materials of analogous character or subject to analogous operations.

A purpose is to impregnate sheet stock such as leather under high pressure adapted not only to pass material into and through leather leather itself.

A further purpose is to support leather by a interference by conditions of the leather itself, with regard to air and moisture.

A furtherpurpose is to take the. air and the moisture from the leather as a preliminary step to impregnation, following this step by application of impregnating material under pressure while the leather is in the prepared condition.

A further purpose is to apply to a charge under hydraulic pressure a sealing pressure due to the same hydraulic pressure which is in excess of the hydraulic pressure itself.

A further purpose is to subject a charge to fluid pressure and to seal ,the charge against escape of fluid by a sealing pressure responsive to variabut to force it into the individual flbers of the J; pregnating material may be permitted without,

tion in the fluid pressure and greater than the fluidpressure.

A further purpose is to seal a material which is to be impregnated by an operation of the press which is doing the impregnating and to intensify the pressure of the seal upon the material being impregnated by reducing the area of the seal as compared with the area of the chamber upon which pressure-is exerted in the press.

A further purpose is to effect a seal against a material being impregnated by diflerential use of the impregnating pressure.

A further purpose is to passimpregnating fluid through a screen-backed material to. -be impregnated so as to completely saturate; the material with impregnating fluid, and to apply it to the material, and subsequently to shut off the exhaust of fluid from the screen so as to raise the pressure throughout the material to be impregnated as compared with the pressure to which, thematerial would be subjected during filtering.

A further purpose is to combine a preliminary filtering operation with a subsequent higher pressure enveloping operation forthe purpose of getting the advantage of both in the. same material to be impregnated.

A further purpose is to provide a press'having a seal which is applied by difierential liquid pressure and in'which the liquiddiiferentialforming the seal is used also for eflecting pressure upon theleather, with or without an intervening protective covering to prevent or to permit impregnationqiot the material being compressed.

(and, where' impregnation isto e permitted, with b without mbacking, which will permit filtration t rough the leather.

' A further purpose is to utilize a fluid-applied seal to a charge being pressed, -which is the material operated upon during a filtering operation as distinguished from a molding operation.

A further purpose is to connect a pressure chamber within which liquid is contained with a pressure gage to indicate the pressure within the chambe Whether the pressure be absolute for pressing purposes or be variant as in filtering or in impregnating operations.

A further purpose is to connect a pressure chamber containing liquid for impregnating purposes, or which is to be filtered, witha pressure gage, interposing a piston or diaphragm between the liquid whose pressure is to be measured and the gage to prevent clogging of the gage by the liquid, preferably using a liquid intermission material within the gage and replacing intermission material by alemiting.

Further purposes will appear in the specification and in the claims.

My invention relates not only to the processes suited to commercial operations but which has been selected primarily by reason of its excellence in illustration of the invention.

Figure 1 is a side elevation 01' a press embodying my invention.

Figure 2 is a right end elevation of the press of Figure 1.

Figure 3 is a section in the plane 3-3 of-Figure 1.

Figure 4 is a section upon the line 4-4 of Figure 3.

Figure 5 is an enlarged fragmentary sectional elevation upon the line 55 of Figure 3.

' Figure 6 is an enlarged section upon the line 6-6 of Figure 1.-

Figure 7 is an enlarged section in the plane 'l-'I of Figure 2, in which portions of the outside screen and of the perforated plate have been broken away.

Figure 8 is an enlarged fragmentary section in the plane 8-8 of Figure 4.

Figure 9 is a section upon the line 9-9 of Figure 8.

Figure 10 is a fragmentary central vertical section, corresponding generally to Figure 4 and showing a different form of my invention.

Figure 11 is an end elevation, half section, of Figure 10.

Figure 12 is a side elevation of a still different form of my invention.

Figure 13 is an end elevation, half section, of Figure 12.

In-Figure 14, a modified form of my invention,

is shown in side elevation. In this figure features of the form of Figures 10 and 11 and also of the form of Figures 12 and 13 are included.

Figure 15 is an end elevation, half section, of

Figure 14. v Figures 16, 16a. and 17 are fragmentary central vertical sections of molds employed in treating sheet material. 1

Figure 18 is a longitudinal section showing application of my,invention to testing a pipe.

In the drawings like numerals refer to like parts.

The mechanism shown is intended to be illustrative merely of one form of mechanism by which the methods can be carried out, it being recognized that the mechanism can be greatly varied both as to the main form and as to the slight modifications illustrated. This mechanism is therefore described for the purpose only of explanation of the invention and not with any thought of restricting the invention by it.

Taking up first the description of Figures 1 to 9:

The main features of the press are old, as well known, and comprise any suitable base or bed 30 and top platen 2] connected by tension bolts 32 which guide a cross head 23, which is moved in the pressure direction by a plunger 24 within a main cylinder 25' and which is moved in the opposite direction by pull-back plungers 36 within pullback cylinders 21. I

It will be obvious that the press can be operated either upwardly or downwardly. The use of a downwardly moved press head, in the present instance, has been dictated purely by economy. The press would operate equally as well in the opposite direction so far as convenience of oper- -ation is concerned, as thelowerhead could have the same character as the lower head shown, whether it be a relatively fixed or relatively movable head.

The cross head is shown as connected by bolts 29 with an upper, in this case a movable die 39, which carries a screen 30. This will be described in more detail later. The main cylinder 25 receives its hydraulic pressure through a pipe 3i. and the pull-back cylinders receive their hydraulic pressure through drained through channels 36 and 31 (Figures 6.

and '7). The channel 31 (Figures 6 and-7) is adapted to receive a pipe 39 connecting with'a stop valve 39 operated by a handle 49, and, when the valve 39 is open, connecting through a pipe 4| (Figure 2) and a flexible hose 42 (Figure 2) with an exhaust 43 preferably through a vacuum pump 44 (Figure 2).

The grooves or channels communicate with the face of the eifective die through apertures 45 (Figure 6) in a perforated plate 46 which is in' tended to mechanically support the work while permitting flow of fluid drained through the apertures and grooves. The perforated plate 46 is preferably not laid directly upon the grooved face of the body of the die for the'reason thlt it is desirable'to have an effective seal between them. For this purpose I have shown a sheet of paper 41 which performs this function quite satisfactorily.

The actual contact with the material to be operated upon is preferably made throughascreen 49, which may conveniently-have a finer mesh than the perforated plate 46, so that for this reason the markings upon the material pressed will be finer and of less destructive nature.

The screen 48 is attached to the head by a steel strap 49 held in place by bolts 50.

In the lower die 5|, I'have shown accommodation for operating on a 'strip of material 52 much longer than it is wide and for this reason, have divided the plunger operation into two parts so that the liquid is forced against the work strip or charge 52 at two points instead of at a single section near the centre. For a strip of material of different shape it would be 'desirable to use a single plunger or a greater number of plungers according to the distribution of fluid to the face of the die which is desired.

The lower die is best seen in Figures 3, 4 and 5 and its sealing face in Figures 8 and 9. As shown, it comprises a base 53 upon which plungers 54 and 55 are secured by bolts 56. The cylinders corresponding to the plungers are found at 51 and 59 and are formed within a pressure head 59. The connection 60 between the cylinders is needed not only to separate the cylinders but to reinforce the head and prevent injury to the cylinders from the internal pressures applied.

The pressure head is intended to slide down and up upon the pistons and is guided in this movement by the pistons themselves;

The pressure head is spring pressed upward by springs 6l to an extent intended to more than support the weight of the pressure head, so that there will be an initial upward pressure upon the work along the line of the sealing surface 62 seen in Figures 3, 4, 5, 8 and 9.

The upward movement of the pressure head is limited by bolts 63.' Leakage past the pistons is prevented by flexible discs 84 held in place by plates 65 fastened in position by screws 66.

By making the pressure head and plunger die the lower die, a liquid which is to be used in it 10 can be poured in through the openings 81 and 88, and the interior space can be cleaned in the depressed position of the pressure head through openings 69 normally closed by plugs Hi. I

The device as so far described is capable of use in several different ways.

The fluid pressure is developed within the cylinder by downward pressure of the pressure head moving the cylinders upon the plungers or pistons as distinguished from moving the plungers or pistons within the cylinders.

With the construction as shown, the fluid pressure thus secured can be used directly to force liquid against the work (for example to pass it through for impregnating purposes or to force it into a pipe or other object to be tested) while holding the seal against the sheet or against the surface of the pipe or other object which is being tested, or by covering with a protective material as in Figure 16, to force the protecting sheet against material (work) to be compressed so as to apply an effectively fluid face pressure against the material to be compressed, making it possible to compress a variant contour of work to the same extent throughout the entire surface pressed.

To recur to one. of the announced purposes of the methodand device. theimpregnation of such a material as leather with a substance carried within the impregnating liquid, the leather is placed upon the sealing face and the upper die is depressed to bring into contact with the leather the screen .or other foraminated surface of the upper die. Enough pressure is applied to compress the springs Ol slightly so as to insure sealing engagement to the surface 62 with the surface of the sheet to be impregnated.

The operation can be performed of course without any special preparation of the leather. or other sheet, but I flnd it to be more effective when the'space above the liquid in the lower die and within the screen and discharge passages of the upper die is evacuated by vacuum means prior to the impregnating operation. This removes the air and moisture which might otherwise retard motion and action of the impregnating liquid.

I find further that the continuance of the vacuum application assists in clearing the passages so as to allow freer and more effective flow of the impregnating liquid.

In my use of the term impregnation, I mean to include any operation which is benefited by the high pressures available, giving a better effect than the mere flowing of a liquid through the most obvious passages within the sheet to be treated, to impregnate or coat fibers which would not otherwise be impregnated or coated or to apply the liquid to a greater depth or to a more effective contact with the surface of the fibers than wouldotherwise take place.

Since the combined area of the ends ll of the cylinders 51 and Bl is much larger than the area 12 within the outer limits ofthe sealing sur face 82, the fluid pressure developed within the cylinder, will be effective to produce a pressure upon the sealing surface considerably in excess of the pressure developed within the cylinders and therefore in excess of the pressure which is exerted upon the work which is. being impregnated or pressed.

The lower die ii is free'to move downward under the action of the upper die. as previously explained, and, as it moves downward about the plungers 54 and 55, causes compression of the liquid within the cylinders 51 and 58, the openings 61 and GI and the depressed space above them. Everywhere throughout the liquid content the pressure is the same, but the force exerted upon various surfaces is a function of their areas.

When equilibrium is established the force upwardly upon the lower die Si is equal to the cross sectional areas of the cylinders 51 and 58 less the cross sectional areas of the openings 61 and 68, all multiplied by the pressure of the liquid, neglecting the effect of the springs 6 i, whose force is trivial in comparison to the large hydraulic forces present. The force downwardly upon the lower die 51 is equal to the force of the upper die on the sealing surface 62, plus the downward force of the liquid on the lower die. The downward force of the liquid on the lower die equals the area inside of the sealing surface 62 less the cross sectional areas of the openings 61 and 68, all multiplied by the pressure.

The force on the sealing surface 62 is therefore equal to the upward force on the lower die 5| minus the downward force on the lower die 5| due to the liquid. Stated in another way, the sealing force is equal to the cross sectional area of the cylinders 51 and 58 minus the area inside of the. sealing surface 82, all multiplied by the pressure. The cross sectional areas of the openings 81 and 68 may be neglected, as they cancel out. The sealing pressure is equal to the sealing force divided by the area of the sealing surface 82, and, as just stated, the sealing force is equal to the difference between the total cross sectional areas of the cylinders 51 and 58' and the area inside of the sealing surface 62, all multiplied by the pressure. Therefore, as long as the total cross sectional areas of the cylinders 51 and 58 are greater than the areas inside of the sealing surface 62 plusthe area of the sealing surface 82, the sealing pressure will be greater than the in the cylinders at all times but increasing with n increase of fluid pressure and reducing with reduction of fluid pressure.

The sealing face 82 preferably covers a considerable total area broken up into spaced ribs I3 producing a general sawtooth effect in cross section as seen in Figure 9. This is for the purpose of producing an artificially extended sealing surface having grooves and ribs of the sealing face of the lower die which engage the work.

Where a pressure is applied directly by the movable head some fairly accurate idea of the effect of pressure on the surface can be obtained from the pressure gage of the intensifier or accumulator pressure applied to the piston or plunger,

but when the pressure is reactionary pressure as in the present case, produced in the fluid content of a two part lower die by reaction against the pressure from the upper die, determination of the pressure by the accumulator or intensifier pressure is not so satisfactory.

For this reason I have provided means for more directly measuring the pressure within a cylinder or the cylinders of the lower die and at i the same time protecting against leakage of the fluid within the lower die. This protectionisdesirable because the liquid within the cylinders of the lower die may be surcharged with impregnating material or for difierent purposes may otherwise be of such constitution that it should be conserved or that it would undesirably effect the pressure gage mechanism used.

In order to measure the pressure of a cylinder or the cylinders in the lower die, I provide a fluid passage ll in communication with the cylinder or cylinders, with which passage a pressure gage I5 is connected through an intermediate chamber 18 within a fitting 11. The chamber 18 accommodates a piston 18, which is packed'at l9 and 80 and which is moved by fluid pressure 'within the passage 14. The piston operates upon a content 8| which may be grease or other suitable material, and which is itself eiIective to operate the pressure gage 15.

The chamber 18 is connected with the pressure gage through a passage 82, which passage is extended at 83 into communication with a valve 84 and a fitting 85, such as of Alemite type, by which, when the valve is open, the filling within chamber 18 may be inserted initially or augmented subsequently to keep the device in operative condition.

Because it is necessary to fill the cavities in the chamber and pressure gage, the filling must be put in under considerable pressure such as is obtainable by the use of a syringe of the Alemite type.

The filling operation isperformed at a time when there is no fluid pressure within the cylinders 51 and 58. After the pressure gage begins to indicate, the valve 84 is closed in order to pro-' tect the fitting 85 from the pressure to which it would be subjected when the fluid pressure is raised in the cylinders 51 and 58.

In Figure 10 the structure is of the same general character and the operation may be the same as in Figure 4, with the exception that the bed or lower part of the lower die is divided to provide two parts 88 and 81, which form a curved joint between them, so that the part 86 can turn in the part 81 to accommodate difference in thicknesses of the material operated upon or variations in position of a piece to which the pressure is to be applied,:as would be the case in variations of position of the flange or of a surface of pipe which is to'be tested by fluid pressure. Where the sealing surfaces (i2 surround an elongated space, such as is shown in Figures 10 and 11, the purpose above would be subserved in large measure by a cylindrical surface only;

between the parts 88 and 81. permitting movement in planes parallel to the planes of the paper, but I have preferred to form a spherical joint 88 between the parts, so that adjustment may take place in all directions until the pressures are equal about the periphery of the sealing surface As long as the lower die is resting upon the bed of the machine, the weight of the parts will hold them together and'no separate means is required to maintain the parts in operative relation. In Figures 14 and 15 where the parts are lifted bodily, provision is made to keep the spherit sockets.

The ball and socket support for the lower die is supplemental and need in no way affect the operation of the rest of the parts of the device. It provides an additional capacity for the additional functionof accommodation of the seal to difierentslopes of surface of the work, automatically taking care of any slope which mayv be present.

Preferably the center of curvature of the ball support lies in the work so that there may be no lateral movement of the sealing surfaces with an accommodation of the seal to the slope but only tilting of the surface.

This is of value in avoiding scraping of the work by the sealing surfaces whether the operation be one of impregnation or one of compres sion.

Where a cylindrical or spherical joint is provided between parts of the base to accommodate for variations in pressure or position of the work with which contact is to be made, it is quite desirable to lubricate this joint and I have taken care of it by allubrication space 89 (Figures 10 and 11) andlubricating passages and 8| connecting with it, the lubricant being introduced by any suitablejmeans.

In Figures 13, i3, 14 and 15 the pressure head of the lower die is supported by hydraulic plungera 92 fitting the hydraulic cylinders 93 which may be additional to the springs '61 or may be used wholly instead of these springs if desired.

In Figures 12 and 13 this feature is applied to a i4 and 15 it is applied to the variation shown in-;

Figures 10 andll.

The difference between Figures 12 and 13 on the one hand, and Figures 14 and 15 on the other hand, due to the difference in structure between Figure 4 for example, and Figures 10 and 11, lies in the fact that in Figures 14 and 15 provision is made for lifting the socket of the ball joint formed between-the parts of the base of the lower die, and not only allowing the two parts of the ball to drop, but providing for additional movement of the pressure head with respect to the base.

In all of Figures 12, 13, 14 and 15, the support of the pressur"head by the hydraulic plungers not only affords a substitute for the springs in whole or in part, but makes it possible by relieving the fluid pressure after operation begins to avoid necessity for compressing against this resilient pressure. The springs or the push-back pistons 82, may still have useful functions in additionaily insuring against loss of seal during the' pressing operation. I

In all of Figures 12, 13, 14 and 15, where the entire base of the lower die is lifted along with the pressure head, the construction makes it possible to effect a reliable seal, at any pressure desired, between the sealing surface 82 and the work before any. fluid pressure is exerted upon the pressure head and to maintain or assist in the seal by the hydraulic pressure provided throughout the entire pressing operation if desired. In this event, the entire lower die is lifted into pressure-sealing engagement with the work after the upper die comes down, or to a positive stop quently pushed down by the upper die until the base comes in contact with the bed of the press,

the use of the hydraulic pressure continuously upon the pressure head causes an additional safeguard against breakage of the seal.

Positive stops for limiting the upward moveisrzent of the pressure head are shown in the bolts In Figures 14 and, 15, the socket 81 is connected with the pressure head by links 95 secured through pins 06 at the bottom and 91 at the top. The pins 91 normally fit into the upper ends of slots 00 in such position as to hold ball and socket members together, while the base parts 06 and 01 are being lifted from the pressure head by means of the hydraulic push-up plungers 92. When the effective seal has been formed above, the position at which development of pressure within the pressure head begins (above, because the pushup plungers have lifted the entire lower die member), further downward movement of the upper die member pushes the entire lower die member downwardly without causing relative movement between the pressure head and the base until the space 99 is closed and the base seats upon the press bed at I00.

In Figure 16, I have shown an upper die I00 which does not have fluid drainage provision, but instead is provided with a face IOI which is suited to give a formation to leather or other sheet material, fibrous or otherwise, which is to be compressed, and Ihave effected the compression by mechanism of the same character otherwise as shown in Figures 1 to 9, except that the fluid pressure of the lower die does not come in direct. contact with the sheet (work) I02, but instead makes the seal at I03 with an intervening flexible protective cover I04 conveniently secured in its position by any suitable means as at I05. The seal is the effective means for holding this protective cover I00 and preventing leakage above it, and the fluid pressure within the space I06 provided by the seal presses against the surface of the cover away from the work, giving uniform pressure upon the work, whether it be of regular or irregular face contour, conforming to irregularities in the surface and effecting resilient pressure compression notwithstanding the irregular- It is thus possible to press work of irregular contour on both sides, producing as in Figure 16a, at I0I, for example, outer and inner generally parallel surfaces of any form determined by the shape of the face of the upper die.

It will be recognized that by shaping the upper foraminous die in Figures 1 to 9 irregularly, the pressure required to force liquid through the work may be made to conform, the work to the irregular shape. of the under face of the upper die before filtration through the work begins, or

70 tective-surface, if the character of the surface of the stock itself be such that aliquid seal may be made with it.

To facilitate the liquid seal on metals, a sealing ring I00 is shown which may be of leather or.

'7- rubber.

This form without a protective surface is effective for any material, where the permeation of liquid through the material at the seal is not too rapid to permit practical sealing at the pressures used, and where the material operated upon is not so porous as to allow the pressure liquid to pass through it before it shallhave been conformed to the shape of the upper die. 1

In Figure 17, I have shown a retaining ring I00 secured to one of the heads, preferably to' the upper head over the screen, and corresponding to the outline of the work upon which we are operating. It is effective during impregnating operations or pressing operations to protect the edges of the material (work) against spreading of the material.

In Figure 18, I have applied my invention to the development and control of pressures within articles (work) to be tested, the particular article shown being a water pipe H0. The die corresponding with the upper die is shown at II I and forms a seal with or without intermediate gasketing at III with the face flange H3 at this end of the pipe.

The plunger or ram H0 in cylinder II5 may be subject to several pressures if it be desirable to work to the best fluid pressure economy. A low pressure supply through inlet H6 is shown to form the initial seal by pressing the opposite end of the pipe against a gasket or other seal- .ing surface III resting upon or integral with the pressure head IIO which is apertured at IIII for the passage of fluid within cylinder I20.

The plunger I2I is supported upon the base I22 and fluid pressure is inserted within cylinder I20 through a pipe I23 valved at I20.

The pipe I23 affords a means of fllling not only cylinder I20 and aperture II 9 with liquid but for filling up the work to be tested; in this case the interior of the pipe with fluid. After this has been accomplished high pressure is introduced to the cylinder II5 through a source of high pressure I25 to cause the plunger or ram III to move the cross head III, moving the pipe and pressure head to make effective pressure thus produced by constricting the space in the cylinder I20. A gage I26 indicates the pressure secured.

The pressure head may be outwardly pressed by the springs shown or by other suitable means and the cross head may be retracted and plunger IIl drawn back by anysuitable push-back or pull-back means, in the present instance shown as a counterweight cord I21 passing over sheave I28 to'a counterweight I29.

In operation of the form shown in Figures 1 to 9, I place impregnating fluid in the depression in the lower die and then insert upon the lower die and in engagement with the sealing edges of the lower die, a sheet to be impregnated.

The spaces within the passages of the usual die and interstices of the sheet to be treated and above the liquid in the lower die are preferably exhausted'of air and moisture by vacuum or other means after the seal has been effected. 'This is for the purpose of having as little interference with complete engagement of the impregnating liquid with the fibres of the sheet as possible.

Theupper die is then depressed by applying pressure to the main cylinder, so that the upper of the springs. As the pressure head ofthe lower die moves downwardly, the impregnating liquid is finally compressed by the plungers in the lower die, thus forcing the sheet firmly against the whole surface of the upper die.

As further pressure is applied to the main ram, the pressure of the impregnating fluid held in the lower die increases, until flnally it is sufficient to force the impregnating fluid into the 10 sheet and finally through the sheet and through the screen upon the lower surface of the upper die. At this point the impregnating fluid is normally removed by suction.

. In passing through the sheet, the impregnating fluid will not only'penetrate all openings in the sheet, but will deposit, in the pores of the sheet, any suspended matter carried by the impregnating fluid. Thus as the impregnating fluid is forced through the sheet, it will leave in the pores of the sheet a progressively-increasing quantity of suspended matter, due to the filtering action of the leather itself.

My lower die is so constructed that the pressure of the sealing surfaces of the lower die against the leather or other material being pressed is in excess of the pressure against the leather. This is due to the fact that the area of the lower die pistons is greater than the area of leather exposed for treatment.

Furthermore, as the pressure in the impregnating fluid builds up, the sealing pressure likewise increases in proportion, always bearing a suitable predetermined relation to the pressure upon the object being pressed. There is thus no 35 danger that the sealing pressure will at any time be too low.

The same method of. applying increased sealing pressure may equally well be used for other purposes, as for example, to engage the ends of piping to hold it in position for bursting tests.

What I have described as impregnating material because of its highly efllbient use in impregnating. leather, for example, might perhaps more aptly be called a treating material jbecause of its broader application to all sorts of uses; and the material used may act upon the workby deposition of suspended matter or by impregnation with liquid having fullydissolved matter in it incapable of being filtered. out b e operation or may be made capable of ch cal reaction upon the interior fibers or surfaces of the sheet.

\ The treatment may be hot or cold, may be successful with different materials for mordant and dye purposes or separate dye purposes or may 55 otherwise be variant for purposes of securing chemical, mechanical or combined results. With a single liquid or where a succession of liquids is used the length of time of treatment with the liquids may become important as also the depth 60 of penetration of the individual liquids into the individual fibers of the sheet, for control of which operations my method of stopping the operation by closing the valve and applying the pressure up to the maximum pressure available is highly 65 effective. This gives control not only of the pressure but of the time of application.

It will be noted that the push-back plungers in :1 Figures 14 and 15 do not engage directly against the under side of the pressure heads but engage with small blocks shown as of the same diameter as themselves which are free to slide against the under face of the pressure head and which have spherical bearing with the plungers whereby the plungers and these blocks together accommodate 75 themselves to'tilting of the pressure head.

accuser As I have shown in Figures 16, 16a, and 17, the same succession of steps minus the discharge of fluid on the other side permitting filtration can be utilized with or without a' protecting surface for application of pressure to compress or to form the work, using the face opposite the effective fluid pressure either as an abutment merely or to give a surface to the material pressed or to control the design or shape of one or both sides of the material pressed.

As shown in figure 18 the same provision for effective pressure may be utilized to apply pressure within a closed receptacle for test purposes.

The variant showings of impregnation, distortion,'die formation of surface, protection of surface, or pressure available for special purposes are all effective along with my sealing means though in Figure .18 there is not the same necessity for the use of this seal as in the other figures. These various forms are given for the purpose of showing the breadth of application of the various features of my invention and to-lay a foundation for divisional applications to cover the processes and apparatus disclosed if it becomes desirable to divide out this subject matter from the present case.

Without attempting to give any considerable number of liquids which may be used, but for v the purpose of showing practical application I would suggest that neats-foot oil, gilsonite oil, carbon tetrachloride, rubber solution, nitro-cellulose solution, grease, colloidal solutions, insecticides and other liquids having solids in solution or suspension may be used to accomplish their now recognized or new benefits and that for pressing purposes oil or water or other suitable content may be used.

It will be evident that my sealing method and mechanism are-effective to hold around the edges a sheet or other material which is to be distorted by pressure, preventing wrinkling duringthe dis torting operation. I

Sealing by axial pressure withthe same area within the seal as within the pressure cylinder, and pressure for impregnating purposes with a seal but without release of the liquid at the back of the sheet to permit flow through are not new to me, and it is not my intention to claim my invention broadly enough to include these.

In view of myinvention and disclosure varia-' tions and modifications to meet individual whim or particular need will doubtless become evident to others skilled in the art, to obtain part or all of the benefits of my invention without copying the structure shown, and I, therefore, claim all such in so far as they fall within the reasonable spiritand scope of my invention. 1

Having thus described my invention, what I claim as new and desire to secure by Letters Patent is:

1. The method of impregnating a material with a substance contained in a liquid which consists in supporting the material by a screened surface to prevent the material from be 1g forced through the screen, while permitting air and liquid to pass through the screen, in forcing liquid containing an impregnating substance through the material at high pressure to deposit the substance upon and within the fibres of the material to be impregnated and in utilizing the pressure of the liquid to form a seal against the material to be impregnated effective as a seal in proportion to the pressure of the liquid.

2. The method of applying increased pressure to a surface or body to which the pressure is to consists in relatively moving the die face and a seal of restricted area to engage the seal with work placed between them and in continuing the relative movement to restrict the volume of a space of greater area than the sealing area to bring pressure of extruded liquid against the material to be operated upon.

4. The method of-impregnating materials or producing pressures upon a surface which consists in providing a seal of limited area about the surface and in relatively moving the seal and a body of fluid of larger cross sectional area than the seal to react through the seal and upon the seal to intensify the pressure upon the seal and produce the pressure required within it.

5. An hydraulic press die comprising relatively movable parts of which the outer part carries a seal and the inner part plunger'means adapted to operate within cylinder means on the inside of the outer part of the die in communication with the space within the seal, the area included within the outside of the seal being less than the cross-' sectional area of the cylinder means.

6. An hydraulic press die comprising relatively movable outer and inner die parts having a seal on the outside of the outer part, cylinder means on the inside of the outer part communicating with the interior of the seal. and of cross-sectional area larger than the area of the outside of the seal and resilient means for pressing the outer part outwardly with respect to the inner part.

7. An'hydraulic press die having a seal upon its outer face and hydraulic means for expressing liquid from the'interior of the die into the space within the seal at a unit pressure less than ,the pressure of the seal against the work in combination with a vacuum filter die and means for closing the outlet to the filter.

8. An hydraulic press die having a seal upon its outer face and hydraulic means for expressing liquid from the interior of the die into the space within the seal at a unit pressure less than the pressure of the seal against the work and ap j, tective face for the work adapted to engage it "e; seal.

9. A die for a press comprising a pressure member carrying a sealing outer face and a cylindered inner face in communication with the space within the seal, plunger means for causing expression of liquid from the cylindered parts with relative movement and resilient means for normally holding theparts separated, the combined cylinder area being in excess of the area included within the outer parts of the seal. v

10. In an hydraulic press a die having a seal upon its outer face and means effective uponpressure against the die for expressing liquid under pressure into the space within the seal of the die and a gasket seal effective between the work and the interior of the seal.

11. .An impregnating press comprising a filter head and a head cooperating therewith having a plunger and an intervening cylinder head surroundingthe plunger and having sealing engagement with the work of smaller area than the cross-sectional area of the plunger.

12. A method of impregnating sheet material with an impregnating fluid, comprising conflning the fluid in a basin, arranging the sheet to be impregnated across the top of the basin, sealing the line of contact between the sheet and the mouth of the basin to prevent the impregnating fluid from escaping through this line, then exerting pressure upon the fluid'in the basin to cause the fluid to move upwardly and penetrate the sheet, and increasing the effectiveness of the seal as the impregnation pressure is increased.

13. An article impregnating apparatus com-" prising a piston member, a cylinder member, said members forming a variable sized basin over the mouth of which the article to be impregnated may be placed, one member being movable relatively to the other, pressure exerting means for causing one of said members to move relatively to the other for forcing an impregnating fluid from the basin into an article arranged across the mouth of the same, and means for effecting a tight seal between the article and the mouth of the basin by the action of the pressure of the impregnating fluid.

14. An article impregnating apparatus comprising a piston member, a cylinder member, said members forming a variable sized basin over the mouth of which the article to be impregnated may be placed, one member being movable relatively to the other, pressure exerting means for causing one of said members to move relatively to the other for forcing an impregnating fluid from the basin into an article arranged across the mouth of the'same, means for effecting a impregnating fluid, and yielding means 'for normally holding said members in definitely spaced relation. a

15. An article impregnating apparatus comprising a piston member, a cylinder member, said members forming a variable'sized basin over the mouth of which the article to be impregnated may be placed, one member being movable relatively to the other, pressure exerting means for causing one of said members to move relatively to the otherfor forcing an impregnating fluid from the basin into an article arranged across the mouth of the same, and means for effecting a tight seal between the articleand the mouth of thebasin by the action of the pressure of the impregnating fluid, the last mentioned means including a shoulder in the cylinder member cooperating with said piston member.

16. An article impregnating apparatus compregnatlng fluid from the basin into an article placed across the. mouth of the basin and for efiecting a tight seal between the mouth of the basin and the article. HENRI P. L. LAUSSUCQ. 

